Reacts violently with fire extinguishing agents such as powder.Depending on the degree of exposure, periodic medical examination is suggested.The symptoms of asthma often do not become manifest until a few hours have passed and they are aggravated by physical effort.Rest and medical observation are therefore essential.Anyone who has shown symptoms of asthma due to this substance should avoid all further contact with this substance.Maleic anhydride is transported also as hot liquid (70°C); contact of the skin should be avoided.The odour warning when the exposure limit value is exceeded is insufficient.